A system provides for the remote activation and deactivation of a downhole tool such as an agitator tool. The downhole tool uses a dart-catching section configured with a profile that engages with a corresponding key section of a dart. Different tools in the string may have different profiles, allowing darts to pass through tools to reach a tool with a matching profile further downhole. The dart includes a removable nozzle that can be detached by a object dropped from the surface, after which a second dart may be dropped to engage with the first dart to change operating parameters of the tool.

A tubing string, such as a coiled tubing or jointed tubing string, has an agitator mounted within an interior of the tubing string at an intermediate position between an uphole end and a downhole end of the tubing string. A tubing agitator is structured to be installed within a tubing string. A method includes: forming or installing a seat within an interior of a tubing string at an intermediate position between an uphole end and a downhole end of the tubing string; and conveying an agitator through the interior of the tubing string until the agitator contacts the seat. A hammer drift tool is also described.

A method and apparatus for casing recovery for well abandonment. A string is run-in, the string including a hydraulic jack (18), an anchor (28), a casing spear (20), a downhole flow pulsing device (22) and a pressure drop sub (24). The casing spear grips an upper end of the length of casing to be pulled. The anchor is set in casing of a greater diameter above the length of cut casing. Fluid pumped through the string and through the pressure drop sub will increase fluid pressure at the hydraulic jack to a first fluid pressure (78). Fluid pumped through the downhole flow pulsing device will vary the fluid flow superimposing a cyclic pressure (82) on the first pressure (78), causing oscillation of an inner mandrel (30) of the hydraulic jack. The jack moves the oscillating inner mandrel upwards relative to the anchor to pull the length of casing.

In a jarring device and method for applying an impact to a casing of a wellbore in a subterranean or subsea formation, the jarring device includes a hammer and a driving means for driving the hammer between a first position in which the hammer is spaced from the casing, and a second position in which the hammer contacts the casing, such that the driving means is operable during use to drive the hammer from the first position to the second position so as to impact the casing. The hammer is reciprocated by the driving means.

A friction reduction system disposable in a wellbore includes a first valve member including an inner surface which includes a valve seat; and a second valve member rotatable concentrically about a central axis of the first valve member and including a radial port coverable by the valve seat of the outer valve member, wherein the friction reduction system includes an open configuration that provides a maximum flow area through a valve of the friction reduction system including the second valve member and the first valve member, wherein the friction reduction system includes a closed configuration that provides a minimum flow area through the valve which is less than the maximum flow area, and wherein the friction reduction system is configured to generate a pressure pulse in a fluid flowing through the friction reduction system in response to the friction reduction system transitioning from the open configuration to the closed configuration.

A pump down intervention tool may be pumped downhole through a work string after an installation of the work string. The pump down intervention tool may include a downhole tool that includes but is not limited to an agitator tool, including but not limited to a fluidic pulsation device, or a check valve. The pump down intervention tool may be pumped downhole in the work string, for example but not limited to in a coiled tubing or jointed pipes. The pump down intervention tool may be landed at a desired location along a length of the work string. The pump down intervention tool can allow for the addition of a downhole tool after the work string's initial deployment, providing a desired functionality downhole at time after the initial deployment of the work string downhole.

A fluidic agitator includes a seamless insert body having an outer enclosure wall defining an enclosed cavity and a plurality of inner channel walls arranged to define an inlet chamber, a vortex chamber, and a feedback chamber within the enclosed cavity. The inlet chamber, the vortex chamber, and the feedback chamber create a hydraulic pulse in a fluid stream received in the enclosed cavity.

A downhole vibration tool includes a body, a mandrel, a spring, and a balance piston. The body may be generally tubular and may have one or more helical slots formed on an inner surface thereof. The mandrel may be generally tubular, may have a bore, and may be positioned at least partially within the body. The mandrel may have one or more helical splines formed on an outer surface of the mandrel, the helical splines engaging the helical slots of the body such that the mandrel is translatable axially relative to the body. The spring may be positioned in an annular space formed between the mandrel and the body defined as a spring chamber. The balance piston may be in an annular space formed between the mandrel and the body, wherein the balance piston separates an oil-filled chamber from an internal pressure chamber.

A downhole tool string for conveying within a wellbore, including an engagement device for engaging a downhole feature located within the wellbore, a first actuator for applying a substantially non-vibrating force to the engagement device while the engagement device is engaged with the downhole feature, and a second actuator for applying a vibrating force to the engagement device while the engagement device is engaged with the downhole feature.

A rotor catch assembly for connection in a workstring in a wellbore is provided. The rotor catch assembly is connected to a downhole motor assembly that includes a rotor that is driven by a fluid. In the normal operating state of the rotor catch assembly, fluid flows through the catch assembly and causes the rotor to rotate. In this state, the catch assembly generates pressure pulses in the fluid in the workstring to facilitate advancement of the workstring in the wellbore. In the event of a failure of a mechanical connection in the motor assembly, the rotor catch assembly shifts to a catch-activated state in which the motor assembly is disabled.